Mitochondrial DNA (mtDNA) accumulates mutations with aging in human beings and animal models of accelerated mtDNA mutagenesis produce advanced aging phenotypes such as osteoporosis, cardiomyopathy, neurodegeneration, hair loss, anemia and reduced fertility. Though compelling, these animal models are insufficient to prove that mtDNA is responsible for aging phenotypes. If mtDNA could be delivered to mitochondria in vivo, the role of mtDNA in aging could be directly addressed. In conjunction with the Center for the Study of Neurodegenerative Disease (CSND) at the University of Virginia, in a Phase I STTR, Gencia Corporation successfully utilized a method to transfect mitochondria with full-length mtDNA. This was done by using a novel mitochondrial transfection technology, Protofection? (Protein Mediated Transfection), a technology developed and solely owned by Gencia Corporation. Protofection is a DNA-binding, non-viral delivery vector consisting of an engineered recombinant protein that targets mitochondria for DNA delivery. Additional data beyond the aims of the Phase I study show that protofection can deliver and express a full-length mtDNA engineered to express a reporter protein (GFP, Green Fluorescent Protein), in vivo and that delivery of normal mtDNA can ameliorate metabolic defects in cytoplasmic hybrid (cybrid) cells made from aged human subjects. The mechanism by which the mitochondrial transfection technology delivers mtDNA to mitochondria was also discovered and suggests the existence of mitochondrial lipid rafts. In this Phase II STTR, Gencia Corporation and the CSND propose to address the contribution of mitochondrial genomic damage to aging phenotypes by transfecting normal mtDNA into aged mice and mtDNA from aged mice into young mice. The proposed mtDNA transfection experiments will directly determine which aspects of aging phenotypes are caused by mtDNA and which can be reversed by the delivery of normal mtDNA. Efficacy in ameliorating specific phenotypes of aging (which may include sarcopenia, cognitive decline, osteoporosis and others) will be the basis of Investigational New Drug (IND) applications to the FDA/CBER (Center for Biologics Evaluation and Research) for the use of mtDNA gene therapy in these conditions. By 2030, an unprecedented 20% of the population will be over age 65. Since mutations in mitochondrial DNA may be responsible for many aging phenotypes, having a therapy for mitochondrial DNA may reduce this burden. The research proposed in this Phase II STTR will directly address what aging phenotypes are caused by mitochondrial DNA and whether these phenotypes can be reversed. [unreadable] [unreadable] [unreadable]